Protocol - D-Link DES-3250TG User Manual

DES-3250TG Layer 2 Fast Ethernet Switch User's Guide
U
NDERSTANDING AND
T
ROUBLESHOOTING THE
When the spanning-tree algorithm determines a port should be
transitioned to the forwarding state, the following occurs:
•
The port is put into the listening state where it receives
BPDUs and passes them to the switch's CPU. BPDU
packets from the CPU are processed. If no BPDUs that
suggest the port should go to the blocking state are
received:
•
The port waits for the expiration of the forward delay
timer. It then moves to the learning state.
•
In the learning state, the port learns station location
information from the source address of packets and
adds this information to its forwarding database.
•
The expiration of the forwarding delay timer moves the
port to the forwarding state, where both learning and
forwarding are enabled. At this point, packets are
forwarded by the port.
S
PANNING
P
ROTOCOL
211
B
T
REE